Advancing into Routing Protocols
In This Chapter
Protocols in this chapter: IP, RIP, OSPF, OLSR, BGP, CIDR
Looking at how packets travel through the TCP/IP layers
Understanding how routers work
Discovering routing protocols
Gorging on routing tables
Putting routing tables on a diet with CIDR
Recognizing attacks on routers
All routers connect networks — small networks, gigantic networks. Every router’s job is to connect networks.
In Chapter 7, you find out how to set up a wireless SOHO (Small Office/Home Office) network. The small multifunction routers shown in that chapter’s SOHO figures connect a home or small office’s subnets to each other — and to the Internet. These small routers can forward packets at a rate ranging from 10 to 20 megabits (millions of bits) per second. That seems plenty fast, but get this: Routers for large private networks (major corporations and organizations) have to be able to forward tens of millions of packets per second. Routers for the Internet forward hundreds of millions of packets per second. Oh, by the way, these big-to-huge routers also cost big-to-huge amounts of money.
No matter how many networks are attached, the router’s job never changes: It connects networks. We can’t say it enough. The job may get more complicated, though, when a router has to figure out where and how to send millions of packets. Special routing protocols help the large routers do their complex jobs.
This chapter introduces some of the added functions, protocols, ...